This invention relates namely to testers for measuring moisture in granular materials such as grain, but also relates to fluid level and temperature indicators, and particularly to testers having probes to be readily inserted into granular materials for determining their characteristics by measuring permittivity and temperature.
Commonly, grain moisture testers have containers into which exact amounts of grain are poured. A sample of grain to be measured often fills space between two electrodes for changing electrical capacitance therebetween. The permittivity of the sample is determined from the capacitance between the electrodes in a filled container. Since the permittivities of different samples depend not only upon the amounts of moisture in the samples but also on their temperatures, temperatures of the samples must be measured and be used in the calibration of the instruments for moisture.
Different samples of grain are taken from storage bins, box cars, and barges to be placed in the moisture testers. Small containers attached to rods as handles may be inserted, opened, closed, and withdrawn to provide samples from different points. The quantity of each sample must usually have to be precisely measured in preparation for measuring moisture.